Bio212 2-8-24 Notes

• Fusiform shape: tapered on both ends
• Convergent evolution is present in fast aquatic swimmers
• 4 types of tissue: epithelial, connective, muscle, and nervous
• Epithelial tissue:

  • Covers the outside of the body and lines the organs and cavities within the body
  • Contains cells that are closely joined
• Connective tissue:

  • Protects, supports, and binds
  • Contains cells including fibroblast and macrophages
• Muscle tissue:

  • Produces movement
• Nervous tissue:

  • Receives stimuli and conducts impulses
• Cells have polarity
• Cells have 2 matrixes, inorganic and organic
• Collagenous fibers provide strength and flexibility
• Elastic fibers stretch and snap back to their original length
• Reticular fibers join connective to adjacent tissues
• Macrophages are part of the immune system
• Fibroblast secretes extracellular fiber proteins
• Loose connective tissue binds epithelia to underlying tissues and holds organs in place
• Fibrous tissue is found in tendons and ligaments
• Tendons attach muscles to bone
• Ligaments connect bones to joints
• Connective tissue mainly binds and supports other tissues. Contains sparsely packed cells scattered throughout, an extracellular matrix consists of fibers in a liquid, jellylike, or solid foundation
• Adipose tissue stores fat for insulation and fuel
• Bone is mineralized and forms the skeleton
• Muscle tissue consists of long cells called muscle fibers, which contract in response to nerve signals
• Skeletal muscle, or striated muscle, is responsible for voluntary movement
• Smooth muscle is responsible for involuntary body activities
• Cardiac muscle is striated, responsible for contraction of the heart, involuntary
• Nervous tissue senses stimuli and transmits signals throughout the animal. Contains neurons and glial cells
• Glial cells help nourish, insulate, and replenish neurons
• Neurons are the functional/structural units
• Hormones are chemical messengers that may affect one or more regions throughout the body, relatively slow acting, but can have long-lasting effects
• Endocrine system is adapted to coordinate gradual changes affecting the body: growth, development, reproduction, metabolic processes, digestion
• Regulating internal change: Animals use internal control mechanisms to moderate internal change in the face of external, environmental fluctuations. Birds and mammals
• Conforming to external environment: Animals allow their internal condition to vary in accordance with external changes in the variable. Fishes and reptiles
• Homeostasis: maintaining a "steady state" or internal balance regardless of external changes, dynamic equilibrium, moderate internal changes
• Homeostasis is controlled by the nervous system and endocrine systems
• Occurs in maintaining "constant" body temperature, blood pH, blood pressure, glucose levels, salts, ions
• Negative feedback: decreases the stimulus, returns a variable to a normal stage
• Positive feedback: amplifies the stimulus and does not usually contribute to homeostasis in animals. Drives processes to completion
• Temporary adjustment acclimatization
• In animals, a circadian rhythm governs physiological changes that occur roughly every 24 hours
• Thermoregulation is the process by which animals maintain an internal temperature within a tolerable range